Switch mounting



w. w. WELCH, SR 2,794,874

SWITCH MOUNTING HIS AT TORNEYJ United States Patent SWITCH MOUNTING William W. Welch, Sr., Cincinnati, Ohio Application August 29, 1955, Serial No. 531,066 2 Claims. (Cl. 200-52) This invention relates to a switch mounting and more particularly to a switch mounting for propeller type fans mounted in housings having cylindrical symmetry, although not necessarily so limited.

In the manufacture of propeller type fans, it is common practice to provide a switch for turning the fan off or on, as well as controlling the speed of operation of the fan. Frequently the off-on control switch is mounted on the motor housing or, when the motor housing is inaccessible, mechanically linked to the motor housing, where it may become subject to excessive mechanical vibration. Attempts to obviate this difliculty by moving the switch from the motor housing to other parts of the fan, such as the fan guard, have been only partially successful because, with fans of cylindrical symmetry, the relocation of the switch results in an asymmetric design.

An object of the present invention is to overcome this difficulty by relocating the oif-on control switch to a position on the fan guard, which is coaxial with the axis of revolution of the fan blades, thus preserving the symmetry of design.

Another object of this invention is to provide a switch mounting for electric fans of cylindrical symmetry which is not linked to moving parts and hence is not susceptible to objectionable vibration.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.

In the drawings, Figure l is a front elevational view of a fan guard similar to that used in the electric fan assembly described in my co-pending application Serial No. 422,036, filed April 9, 1954. At the center of this fan guard is shown a switch actuator knob.

Figure 2 is an enlarged fragmentary view of the central portion of the fan guard without the switch actuator knob.

Figure 3 is a cross sectional view, taken substantially along the line 33 in Figure 1, showing the switch mounting assembly in relation to the cylindrical cup-shaped or bell-shaped cavity at the center of the circular fan guard.

Referring more in detail to the figures, a circular fan guard has a cylindrical hub 12 with a wall perpendicular to the plane of the fan guard. Mounted within this cylindrical hub 12 by means of spokes 14 is a hollow portion 16. At the center of the base of the hollow portion 16 is cut a longitudinal slot 18 with arcuate ends. Fitted within the hollow portion 16 is a cylindrical switch housing 20 which contains a switching mechanism (not shown). A tubular fiat-sided shaft 22, which also has threaded arcuate sides, is attached to the switch housing 20. The tubular flat-sided shaft 22 projects through the longitudinal slot 18 and is locked in place by a hexagonal nut 24. Projecting through and beyond the tubular fiatsided shaft 22 is a circular switch actuator shaft 26, which terminates in a coupling portion 28 which may have a square cross section. In the end of the coupling portion 28 of the circular switch actuator shaft 26 is an internally threaded axially extended hole 29.

Attached to the circular shaft 26 is an approximately frustum-shaped hollow switch actuator knob 30 which has a coupling portion 32 complementary to the coupling portion 28 of the circular switch actuator shaft 26. The switch actuator knob 30 is locked to the switch actuator shaft 26 by means of a round headed screw member 34, which penetrates the center of the switch actuator knob 30 to engage the threads of the hole 29. The frustumshaped switch actuator knob 30 is so constructed that it fits into the channel between the wall of the cylindrical hub 12 and the hollow portion 16, so as to cover and conceal this hollow portion 16. Instead of a frustumshaped hollow switch knob, any other suitable switch knob may be used.

The operation of an electric fan embodying this device is regulated by rotating the switch actuator knob to any desired position as may be indicated by an arrow inscribed on the switch actuator knob, cooperating with legends describing the fan operation, such as Off, On, Fast, Slow, et cetera, inscribed on the face of the fan guard.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A circular fan guard having a cylindrical hub with a wall perpendicular to the plane of the fan guard, a hollow portion having at its base a longitudinal slot with arcuate ends, spokes directed radially which hold said hollow portion in the center of said cylindrical hub, a switch housing with a tubular fiat-sided shaft attached thereto, said flat-sided shaft having also threaded arcuate sides, said flat-sided shaft projecting through and seated in said longitudinal slot, a nut threadedly connected to the arcuate sides of said tubular fiat-sided shaft so as to lock said switch housing within said hollow portion, a circular switch actuator shaft passing coaxially and rotatably through and projecting beyond said tubular fiat-sided shaft, said switch actuator shaft terminating in a square portion forming a coupling portion, said circular switch actuator shaft having at its terminus a threaded cylindrical cavity coaxial with the shaft, a switch actuator knob of hollow frustum-shape having a coupling portion which complements and engages the coupling portion of the switch actuator shaft, said switch actuator knob being seated rotatably within the cylindrical wall at the hub of the fan guard so as to cover and conceal the hollow portion at the center of the fan guard, and a screw member which penetrates the center of said switch actuator knob to engage the threads of the cylindrical cavity in the switch actuator shaft, thereby locking the switch actuator knob to the switch actuator shaft.

2. A circular fan guard having at its center a hollow portion in the center of which is a longitudinal slot with arcuate ends, a switch housing with a tubular fiat-sided shaft attached thereto, said fiat-sided shaft having also threaded arcuate sides, said flat-sided shaft projecting through and seated in said longitudinal slot, a nut threadedly connected to the arcuate sides of said tubular flatsided shaft so as to lock said switch housing within said hollow portion, a circular switch actuator shaft passing coaxially and rotatably through and projecting beyond said tubular flat-sided shaft, said switch actuator shaft terminating in a coupling portion, said circular switch actuator shaft having at its terminus a cylindrical threaded cavity coaxial with the shaft, a switch actuator knob of hollow frusturn shape having a coupling portion which complements and engages the coupling portion of the switch actuator shaft, said switch actuator knob being so constructed that it covers and conceals the hollow bellshaped portion at the center of the fan guard, and a screw member which penetrates the center of said switch actuator knob to engage the threads of the cylindrical cavity in the switch actuator shaft, thereby locking the switch actuator knob to the switch actuator shaft.

References Cited in the file of this patent 

